Method of Radiographic Examination for welded T Joint in a Flue and Smoke-Tube Type Boiler

Abstract

If a shell or flue is welded to a tube plate by T(tee) joint, remarkable thermal stress will occur at the welded parts owing to the temperature difference between shell and flue. Therefore, welded parts shall be inspected by radiographic examination precisely, but it is not so easy to carry out this examination because of complexity of such a boiler. In order to establish an acceptable method of radiographic examination, author made the test plates by the same welding procedure as applied for actual boilers, and examined the welded parts radiographically at various conditions. Authors has also studied on the relationship between film exposure and thickness of welded part to keep sufficient penetrant performance through the whole length of welded length of welded T joint.